One way of biomass and/or waste recycling is its thermochemical conversion into combustible gas. Mainly composed of CO,H 2 and CH 4 , the gas may also contain varying amounts of impurities (dust, polluting products, tar or soot). Specifically, there is a tar problem: their high condensation temperature is incompatible with an industrial utilization. They can cause rapid fouling, corrosion and abrasion into turbines or engines. Proposed by EUROPLASMA, the CHO-Power process aims to generate electricity from a mixture of municipal waste and biomass using a fixed bed gasifier with conventional gas treatment. Its specificity consists of an unit called Turboplasma. This stage allows to reach very high temperature in order to obtain temperature around 1600K, and so to degrade all tars present, even heavier. Indeed, EUROPLASMA built a gasification pilot unit based on fluidized bed technology, (called KIWI) to qualify the synthesis gas produced. TURBOPLASMA pilot scale will be installed there. The objective of this work is the design of this high temperature stage thanks to numerical modeling. Reaction scheme used previously [4] to modelize tar degradation in the Turboplasma of CHO-Power, has been improved: a discrete phase modeling has been added providing a better view of the TURBOPLASMA internal behavior. Indeed, char particles from syngas can significantly change the reactor performance. This study shows that char particles react primarily with the H 2 O and CO 2 . Char gasification takes place in areas of high velocity and temperature gradient. Increased understanding of aerodynamics inside the reactor allows a better estimate of the overall performance of the reactor. Performance evaluation of the reactor is based on a set of parameters such as levels of heat loss, velocity gradient, mixing quality, residence time.

A great deal of recent commercial interest in gasification technology has been centered on the idea of conditioning the producer or syn-gas generated to a level suitable for inclusion in an internal combustion (IC) engine power generation in the 3–15 MW range. Ideally the feed stocks for the gasification system should be able to encompass a variety of opportunity fuels to reduce the energy input costs to the engine. However, these opportunity fuels can cover a wide variety of potential energy sources such as refuse derived fuels, recovered plastics, and various grades of woody biomass, which can present operational challenges to the successful operation of an IC engine. Most major IC engine manufacturers have published guideline specifications for acceptable levels of particulate matter, sulfur, halogens, trace metals, and tar dew points to be maintained in handling a gasification producer gas. The requirements can be very rigorous especially in the context of variable feed mixtures and operational variations encountered in gasification of opportunity fuels. This presentation will address commercial research efforts to adapt an emerging air pollution control technology, the EISENMANN WESP-2F, as the desired technical solution for appropriately conditioning gasification producer gas to a point where inclusion in an IC engine is feasible. Research and testing on the aforementioned system took place using a pilot sized unit operating a slipstream off a commercial sized gasifier testing a number of opportunity fuels. Technical challenges encountered and lessons learned are recounted.

Landfills are the second-largest source of anthropogenic methane emissions in the U.S., accounting for 22% of CH 4 emissions. Landfill gas (LFG) is primarily composed of CH 4 and CO 2 , and currently only 18% of this is used for energy. Because landfills will continue to be used for the foreseeable future, complete utilization of LFG is becoming more important as the demand for energy increases. Catalytically reforming LFG produces syngas (H 2 and CO) that can be converted to liquid fuels or mixed into the LFG stream to produce a more reactive, cleaner burning fuel. It has been demonstrated that injecting 5% syngas into a simulated LFG mixture prior to engine combustion decreases CO, UHC, and NO x emissions by 73%, 89%, and 38%, respectively. One barrier to using LFG in a catalytic system is the contaminant content of the LFG, including chlorine and sulfur compounds, higher order hydrocarbons, and siloxanes that have the potential to poison a catalyst. Chlorinated compounds are present in LFG at 10–100ppm levels and are often found as chlorocarbons. This research explores the effect of methyl chloride on the activity of a Rh/γ-Al 2 O 3 catalyst while dry reforming LFG to syngas. It has been found that methyl chloride acts as a reversible poison on the dry reforming reaction, causing a loss in dry reforming activity, decrease in syngas production, and increase in H 2 /CO ratio while CH 3 Cl is present in the feed. CH 3 Cl exposure also decreases the acidity of the catalyst which decreases carbon formation and deactivation due to coking.

Covanta Energy, in cooperation with United Technologies Corporation (UTC), has evaluated, designed, and is in the process of installing an Organic Rankine Cycle (ORC) system at its Haverhill Energy from Waste (EfW) Facility to improve heat recovery and energy efficiency, and to generate more clean renewable energy. ORC systems have been applied in geothermal applications and some other industrial processes to recover low grade and waste energy to generate electricity. This paper describes the design and integration of the ORC system into the Haverhill EfW steam cycle, and the landfill gas engine system, which also operates at the facility. The anticipated energy efficiency improvements and increased net power output have been analyzed and simulated. The results show that the integration of the ORC system could lead to a potential increase in the net power output by as much as 305 kWe in the summer and by 210 kWe in normal weather. It is also anticipated that with the ORC system the facility has the potential to improve the overall plant energy efficiency, as well as save city water.

The size of combustion generated particles ranges from a few nanometers up to 1 micron, whereas the size of naturally occurring PM such as pollens, plant fragments, and sea salt is generally larger than 1 micron. Particles generated by photochemical processes in the atmosphere are generally smaller than 1 micron. Ultrafine particles (UFP), also called “nanoparticles”, are <0.1 micron and in recent yearshave attracted attention due to potential adverse health effects associated with them. The contribution of UFP to the total PM mass is very small. However, they dominate the total number of particles in urban aerosols. Their sources are both mobile and stationary combustion sources and also gas-to-particle conversions. In coal and waste combustion systems, UFP are hypothesized to be generated mainly by nucleation of metal vapors. Coal naturally contains a vast range of inorganic elements among which are heavy metals. Sources of heavy metals in MSW include batteries, electronic devices, light bulbs, house dust and paint chips, food containers, used motor oils, plastics, yard wastes and some papers. The input of these metals into WTE facilities can be controlled by better source-separation of metal-containing materials. In 2007 almost 50% of the approximately 4.16 billion MWh generated in the United States was produced by coal power plants whereas only 0.3% was generated by the WTE industry. A preliminary study has shown that in terms of contribution to UHF in the atmosphere, MSW combustion has a minor effect in comparison to coal-fired power plants in the U.S. This paper will report on the results of this investigation.

Air-Cooled Condenser performance can significantly affect WTE plants bottom-line. Most of the possible ACC performance improvement solutions require some important capital costs (fin tubes replacement, fans blades or motor upgrade, additional ACC cells, addition of preventive air re-circulation panels, etc…). A new low cost tool and methodology is now allowing to gain a very detailed understanding of ACC behaviours and to optimize ACC operations and cleaning schedules. This article is illustrated by the case-study of a WTE located in the south of France (equipped with a 5.5 MW GE condensing turbine), where the facility performance was strongly limited by its ACC, and where additional turbine generator output of more than 1 MW were achieved.