This paper summarizes the findings involved in the development of producer gas fuelled reciprocating engines over a time frame of six years. The high octane rating, ultra clean, and lowenergy density producer gas derived from biomass has been examined. Development efforts are aimed at a fundamental level, wherein the parametric effects of the compression ratio and ignition timing on the power output are studied. These findings are subsequently applied in the adaptation of commercially available gas engines at two different power levels and make. Design of a producer gas carburettor also formed a part of this developmental activity. The successful operations with producer gas fuel have opened possibilities for adapting a commercially available gas engine for large-scale power generation application, albeit with a loss of power to an extent of 20-30 per cent. This loss in power is compensated to a much larger extent by the way toxic emissions are reduced; these technologies generate smaller amounts of toxic gases (low NO x and almost zero SO x ), being zero for greenhouse gas (GHG).

No abstract

The paper presents the performance of a diesel engine coupled to a biomass gasifier in the dual fuel operation. The paper addresses a methodology and analysis towards choice of a diesel engine to meet the specific power requirement. Performance evaluation of both the engine and the gasification system is reported. Diesel savings in excess of 75% have been achieved. The specific fuel consumption is about 1 kg of biomass and 46 g of diesel per kilowatt hour of electricity, amounting to an overall efficiency of 22% in the dual fuel compared with 28% in the diesel engine operation. The overall energy balance indicates that the heat loss through the engine exhaust is high in the case of dual fuel mode of operation. The specific energy consumption is 17 MJ/kWh in the dual fuel mode. Engine exhaust emissions, CO and NO x , in diesel and dual fuel modes are compared.

In the recent times issues like the Green House Gas (GHG) emission reduction and carbon-trading through Clean Development Mechanism (CDM) have gained large prominence as a part of climate change. Biomass gasification is one such technology which is environmentally benign and holds large promise for the future. These technologies are currently being utilized for power generation applications at a number of industrial sites in India and abroad. This paper summarizes the work conducted using biomass derived producer gas in reciprocating internal combustion engines. The producer gas for the experimental work is derived from the well-established open top, re-burn, down draft gasification system, which is proven to generate consistent quality, ultraclean producer gas. This paper discusses the actual emission measurements in terms of NOx and CO on (a) dual-fuel engine (compression ignition engine) -using high speed diesel and producer gas fuel, (b) gas engine (spark ignited engine) -using 100% ultra clean producer gas. In the case of dual-fuel operation it is found that the NOx levels are lower compared to operations with pure diesel fuel on account of lower peak flame temperature, whereas the CO levels were higher due to combustion inefficiencies. In the case of gas alone operation it is found to be environmentally benign in terms of emissions; NOx and CO levels are found to be much lower than most of the existing emissions norms of various countries including the United States and European Union.

This article presents the studies conducted on turbocharged producer gas engines designed originally for natural gas (NG) as the fuel. Producer gas, whose properties like stoichiometric ratio, calorific value, laminar flame speed, adiabatic flame temperature, and related parameters that differ from those of NG, is used as the fuel. Two engines having similar turbochargers are evaluated for performance.Detailed measurements on the mass flowrates of fuel and air, pressures and temperatures at various locations on the turbocharger were carried out. On both the engines, the pressure ratio across the compressor was measured to be 1.40 AE 0.05 and the density ratio to be 1.35 AE 0.05 across the turbocharger with after-cooler. Thermodynamic analysis of the data on both the engines suggests a compressor efficiency of 70 per cent. The specific energy consumption at the peak load is found to be 13.1 MJ/kWh with producer gas as the fuel. Compared with the naturally aspirated mode, the mass flow and the peak load in the turbocharged after-cooled condition increased by 35 per cent and 30 per cent, respectively. The pressure ratios obtained with the use of NG and producer gas are compared with corrected mass flow on the compressor map.