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Publications


2019

Johnson, MA, Garland CR, Jagoe K, Edwards R, Ndemere J, Weyant C, Patel A, Kithinji J, Wasirwa E, Nguyen T, Khoi DD, Kay E, Scott P, Nguyen R, Yagnaraman M, Mitchell J, Derby E, Chiang RA, Pennise D.  2019.  In-Home Emissions Performance of Cookstoves in Asia and Africa. Atmosphere. 10(5):290. AbstractWebsite

Abstract
This paper presents results from eight field studies in Asia and Africa on the emissions performance of 16 stove/fuel combinations measured during normal cooking events in homes. Characterizing real-world emissions performance is important for understanding the climate and health implications of technologies being promoted as alternatives to displace baseline cooking stoves and fuels. Almost all of the stove interventions were measured to have substantial reductions in PM2.5 and CO emissions compared to their respective baseline technologies (reductions of 24–87% and 25–80%, for PM2.5 and CO emission rates, respectively), though comparison with performance guidance from the World Health Organization (WHO) and the International Organization for Standardization (ISO) suggests that further improvement for biomass stoves would help realize more health benefits. The emissions of LPG stoves were generally below the WHO interim PM2.5 emissions target (1.75 mg/min) though it was not clear how close they were to the most aspirational ISO (0.2 mg/min) or WHO (0.23 mg/min) targets as our limit of detection was 1.1 mg/min. Elemental and organic carbon emission factors and elemental-to-total carbon ratios (medians ranging from 0.11 to 0.42) were in line with previously reported field-based estimates for similar stove/fuel combinations. Two of the better performing forced draft stoves used with pellets—the Oorja (median ET/TC = 0.12) and Eco-Chula (median ET/TC = 0.42)—were at opposite ends of the range, indicating that important differences in combustion conditions can arise even between similar stove/fuel combinations. Field-based tests of stove performance also provide important feedback for laboratory test protocols. Comparison of these results to previously published water boiling test data from the laboratory reinforce the trend that stove performance is generally better during controlled laboratory conditions, with modified combustion efficiency (MCE) being consistently lower in the field for respective stove/fuel categories. New testing approaches, which operate stoves through a broader range of conditions, indicate potential for better MCE agreement than previous versions of water boiling tests. This improved agreement suggests that stove performance estimates from a new ISO laboratory testing protocol, including testing stoves across low, medium, and high firepower, may provide more representative estimates of real-world performance than previously used tests. More representative results from standardized laboratory testing should help push stove designs toward better real-world performance as well as provide a better indication of how the tested technologies will perform for the user. View Full-Text
Keywords: household energy; solid fuel; biomass; stove performance; emission factors; black carbon

2014

Njenga, M, Karanja N, Karlsson H, Jamnadass R, Iiyama M, Kithinji J, Sundberg C.  2014.  Additional cooking fuel supply and reduced global warming potential from recycling charcoal dust into charcoal briquette in Kenya. Journal of cleaner production. 81:81-88. AbstractWebsite

Abstract

Rising demand for energy is one of the major challenges facing the world today and charcoal is a principal fuel in Kenya. Faced with energy poverty many poor households turn to briquette making. This study assessed the additional cooking fuel obtained from recycling charcoal dust into charcoal briquettes. It applied Life Cycle Assessment (LCA) to assess the global warming potential (GWP) from use of charcoal and production of briquettes from charcoal dust and cooking a traditional meal for a standard household of five people. Native vegetation of Acacia drepanolobium and a low efficiency kiln were considered the common practice, while an Acacia mearnsii plantation and a high efficiency kiln was used as an alternative scenario. Charcoal and kerosene were considered as reference fuels. Recovering charcoal dust for charcoal briquettes supplied an additional 16% cooking fuel. Wood carbonization and cooking caused the highest GWP, so there is a need for technologies to improve the efficiency at these two stages of charcoal briquettes and charcoal supply chain. Supplying energy and cooking a traditional meal in a combined system using charcoal and recovering charcoal dust for charcoal briquettes and charcoal alone accounted for 5.3–4.12 and 6.4–4.94 kg CO2 eq. per meal, respectively, assuming trees were not replanted. These amounts declined three times when the carbon dioxide from the carbonization and cooking stages was assumed to be taken up by growing biomass. This requires replanting of trees cut down for charcoal if the neutral impact of biomass energy on GWP is to be maintained.

Nkonge, AN, Magambo JK, Kithinji J, Mayabi AO, Taratisio N.  2014.  Management of healthcare waste in national teaching and referral hospitals in Kenya. International Journal of Environment and Waste Management. 14(2):199-209. AbstractWebsite

Abstract

Healthcare waste management in health facilities should include quantification of all categories to support minimisation strategies. The hazardous healthcare waste categories under study, infectious, pathological, sharps and chemical waste were weighed in the two teaching and referral institutions, Kenyatta National Hospital (KNH) and Moi Teaching Hospital (MTRH) during the wet and dry season. The comparison for the two hospitals, during the wet season was significant for infectious waste (0.0001) but not so for pathological waste (p = 0.7393) and sharps waste (p = 0.3363). During the dry season, coefficient of variation for the two hospitals was significantly different, infectious waste (p = 0.0027) and pathological waste (p = 0.0086). Sharps waste was not significant (p = 0.3615). The studied hazardous healthcare waste generation rate was 0.61 kg/bed/day for KNH and 1.03 kg/bed/day for MTRH. The two institutions should practice healthcare waste minimisation and segregate their waste accurately.
Keywordshealthcare waste, segregation in categories, quantification, referral hospitals

2013

Njenga, MM.  2013.  Evaluating Fuel briquette technologies and their implications on Greenhouse gases and livelihoods in Kenya. , Nairobi: University of Nairobi Abstract

Description
Charcoal is the principal cooking fuel in Kenya which provides energy to 82% of urban and 34% of rural households. Poor households are opting to use unhealthy sources of fuel such as tyres, old shoes and plastics especially those in urban and peri-urban areas while many families are shifting from traditional meals that require long cooking times and are compromising dietary diversity and nutrition as a result. Faced with poverty and unemployment, communities are turning to fuel briquette which is made by compressing biomass material into a solid unit. Fuel briquette production methods in Nairobi and surroundings and their implications on the quality of the product were studied through focus group discussions with eight groups and one private company. The fuel briquette producing community SHG‘s in Nairobi comprised all those identified and located using an existing database on self-help groups involved in waste management in Nairobi. One group SHG that produced sawdust fuel briquettes was identified in Naro Moro through PactKe an NGO working on Natural Resource Management in Laikipia county. Implications of fuel briquettes on the community livelihoods were also investigated. Theresults obtained were applied in designing experiments to assess different fuel briquettes producing techniques using, (i) different binders namely soil, paper, cowdung and gum Arabica, (ii) pressing machines, (iii) charcoal dust from Acacia mearnsii, Eucalyptus spp and Acacia xanthophloea,(iv) sawdust from Grevillia robusta, Pinus patulaandCupressus lusitanica and (v) carbonized sawdust from the three tree species above in (iv).combustion …

Njenga, M, Karanja N, Munster C, Iiyama M, Neufeldt H, Kithinji J, Jamnadass R.  2013.  Charcoal production and strategies to enhance its sustainability in Kenya. Development in Practice. 23(3):359-371. AbstractDevelopment in Practice

Description
In sub-Saharan Africa, 72 per cent of urban and 98 per cent of rural households use fuelwood for energy. In Kenya use of charcoal in urban areas has risen by 64 per cent in two decades. Despite the charcoal industry providing employment to 500,000 people and generating over US $427 million that benefits grassroots communities, it has been kept out of the formal economies of this country. This review presents the status of the charcoal industry in Kenya, highlighting its contribution to livelihoods, production, utilisation, and implications for the environment; policy issues; and stakeholders' involvement. The review also proposes strategies to improve the sustainability of this sector.

Njenga, M, Karanja N, Jamnadass R, Kithinji J, Sundberg C, Jirjis R.  2013.  Quality of cooking fuel briquettes produced locally from charcoal dust and sawdust in Kenya. Journal of Biobased Materials and Bioenergy. 7(3):315-322. AbstractJournal of Biobased Materials and Bioenergy

Description
Fuel briquettes are made by compressing biomass material into a uniform solid and present an opportunity for good quality cooking fuel. The study evaluated the quality of locally produced fuel briquettes in Kenya and their combustion properties, chemical composition and emissions of gases and fine particulate matter. Briquette made from charcoal dust bonded with paper, soil or corn starch and sawdust briquettes bonded with gum arabica were studied. Charcoal dust briquettes bonded with corn starch or paper had the highest calorific values of 23.6 kJ/g and 21.4 kJ/g respectively. Contaminants comprising of chromium, mercury and lead were high in briquettes made from material sourced from garbage heaps in informal settlements and dumpsites. Charcoal dust briquettes bonded with soil was the safest in terms of indoor air concentrations of carbon monoxide and fine particulate matter when burned. Burning …

Kithinji, J.  2013.  Genetic divergence in Jatropha curcas L., a potential biofuel crop in Kenya. Future science Journal. 4(3):313-322.

2012

Njagi, NA, Oloo MA, Kithinji J, Kithinji MJ.  2012.  Health-care waste incineration and related dangers to public health: case study of the two teaching and referral hospitals in Kenya. Journal of community health. 37(6):1168-1171. Abstract

Description
There are practically no low cost, environmentally friendly options in practice whether incineration, autoclaving, chemical treatment or microwaving (World Health Organisation in Health-care waste management training at national level, [2006] for treatment of health-care waste. In Kenya, incineration is the most popular treatment option for hazardous health-care waste from health-care facilities. It is the choice practiced at both Kenyatta National Hospital, Nairobi and Moi Teaching and Referral Hospital, Eldoret. A study was done on the possible public health risks posed by incineration of the segregated hazardous health-care waste in one of the incinerators in each of the two hospitals. Gaseous emissions were sampled and analyzed for specific gases the equipment was designed and the incinerators Combustion efficiency (CE) established. Combustion temperatures were also recorded. A flue gas analyzer …

Njagi, NA, Oloo MA, Kithinji J, Kithinji MJ.  2012.  Knowledge, attitude and practice of health-care waste management and associated health risks in the two teaching and referral hospitals in Kenya. Journal of community health. 37(6):1172-1177. AbstractJournal of community health

Description
Hazardous health-care waste poses a great danger to public health and the environment if it is not properly managed. There is need for health-care workers involved in its management to understand the integral link between human health and environmental health. This study was done to identify gaps in knowledge, attitude and practice among the healthcare workers involved in its management hence endangering public health and polluting the environment. A self administered questionnaire was used in both Kenyatta National Hospital, Nairobi and Moi Teaching and Referral Hospital, Eldoret to clinicians, nurses, laboratory technologists and hospital attendants to identify the gaps with a focus on their knowledge, attitude and practice. It was found that health and safety in health-care waste management, was not included in most of the curricula for training the three healthcare professionals. Most of them …

2005

2001

Pennise, DM, Smith KR, Kithinji JP, Rezende ME, Raad TJ, Zhang J, Fan C.  2001.  Emissions of greenhouse gases and other airborne pollutants from charcoal making in Kenya and Brazil. Website

1989

Barkera, IK, Bartlea KD, Clifforda AA, Kithinji JP, Shilstonea GF, Phillips TR, Thomas G.  1989.  Separation of compounds from gasifier tars by extraction with supercritical carbon dioxide. AbstractWebsite

Coal gasification tars were extracted with supercritical carbon dioxide at different temperatures and pressures, and the properties of the extraction residues (pitches) were determined by elemental analysis, size-exclusion chromatography and simulated distillation. Extract fractions were analysed by supercritical fluid chromatography. The pitches generally had softening points near the temperature of extraction. Raising the extraction temperature at constant pressure reduces the solvent density, and hence reduces the solubility of tar constituents. Extraction is optimized by extracting at low flow rates, initially at low temperature (high density) to remove low molecular mass compounds, and then increasing the temperature to ensure good contact with molten pitch and increasing the pressure to increase the density. Contact with powdered pitch is preferable. In agreement with calculated solubilities, polycyclic aromatic hydrocarbons, especially naphthalene, fluorene and phenanthrene, are the principal constituents of the extracts. More polar compounds remain in the pitch.

P, DRKITHINJIJACOB.  1989.  Unified multidimensional microcolumn chromatography.. J. Microcoloumn Separations. : University of nairobi Abstract
Abstract in Bellamy, M. and B. Greenshields (eds), Issues in Agricultural Development: Sustainability and Cooperation. IAAE Occasional Paper No. 6. Dartmouth Publishing Co. Ltd, Aldershot.
P, DRKITHINJIJACOB.  1989.  Chromatography with supercritical fluids, in Piggott and A. Paterson (eds) Distilled beverage flavour: Recent developments.. VCH Publishers, Cambridge, U.K.. : University of nairobi Abstract
Abstract in Bellamy, M. and B. Greenshields (eds), Issues in Agricultural Development: Sustainability and Cooperation. IAAE Occasional Paper No. 6. Dartmouth Publishing Co. Ltd, Aldershot.

1988

P, DRKITHINJIJACOB.  1988.  Supercritical fluid chromatography of ecdsteroids.. J. Chromatogr. 436 ( 497-502).. : University of nairobi Abstract
Abstract in Bellamy, M. and B. Greenshields (eds), Issues in Agricultural Development: Sustainability and Cooperation. IAAE Occasional Paper No. 6. Dartmouth Publishing Co. Ltd, Aldershot.
P, DRKITHINJIJACOB.  1988.  LC-GC, SFC-GC and SFC and SFE-GC interfacing.. Anal. Chem. 60 (1988) 683-702A.. : University of nairobi Abstract
Abstract in Bellamy, M. and B. Greenshields (eds), Issues in Agricultural Development: Sustainability and Cooperation. IAAE Occasional Paper No. 6. Dartmouth Publishing Co. Ltd, Aldershot.
P, DRKITHINJIJACOB.  1988.  Studies of the temperature dependence of retention in supercritical fluid Chromatography.. J. Chem. Soc. Faraday Trans. 84(12), (1988) 4487-4493.. : University of nairobi Abstract
Abstract in Bellamy, M. and B. Greenshields (eds), Issues in Agricultural Development: Sustainability and Cooperation. IAAE Occasional Paper No. 6. Dartmouth Publishing Co. Ltd, Aldershot.

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