- Is waste sorting primarily a manual process?
- How much feedstock is needed for each day? And what is the moisture content of the feedstock and how much carbon is produced?
- Except for carbon, what other remnants and byproducts are produced?
- What is the contamination level of these solids? Can they be placed in a landfill without further treatment?
- Is the quoted 5 MW per hour, i. e., 5 MWh?
- As for the unit, what is the minimum footprint requirement (12,000 sq feet) and what does the term mobile imply?
- Why is devolatization more effective?
- What is Starved Air Gasification?
- What is the process for establishing or connecting to power grid?
- Why is the amount of Btu for the unit lower than the Btu of a standard natural gas?
Is waste sorting primarily a manual process?
This depends on the clients needs. We can provide MSW handling/sorting/grinding systems based on needs. Some clients want to "create more jobs", therefore they go with a more manual process. Other clients want a fully automated system. We can provide a system that maximizes manual labor, or completely automates, or something between the two.
How much feedstock is needed for each day? What is the moisture content of the feedstock and how much carbon is produced?
The unit processes 30 tons of feedstock per day with a 24-hour operation and can produce 1.25 MW of energy depending on the feedstock. If you want to produce more energy or process more volume you simply add another 1.25 MW to the process. As for the moisture content, the unit is built to remove all but 3-6% moisture by weight automatically prior to entry into the reactor vessel by squeezing it out. The carbon produced is somewhat dependent on the feedstock. As a rule of thumb we convert 80% to gas and 20% to carbon. So based upon 24 hours of operations a 1.25 MW system would produce 6 tons of carbon per day.
Except for carbon, what other remnants and byproducts are produced?
The system produces two products, gas and carbon, both of which have revenue value. Additionally, some clean grit is produced and potentially some longer-chain oils and tars that may be collected and sold in the chemical and pharmaceutical industries. In the event they cant be sold as such, the oils and tars can be mixed and sent back through the system. Since they are long chain hydrocarbons, they will react like any other feedstock. The oils and tars would be mixed with the other feedstock and broken back into their elements. New hydrogen would bond to the carbon molecules making more gas.
What is the contamination level of these solids? Can they be placed in a landfill without further treatment?
The answer depends on the mixture of MSW input. Assuming normal suburban landfill material (no toxic waste), the material is clean and inert and can be used in road and building applications. Therefore, the material can be landfilled without treatment. In the case of there being hydrocarbon impurities present, we would not landfill, just rerun. For heavy metal or other inorganic impurities, the material could either be sequestered or post-processed to both purify the resulting carbon and inorganics, which may have commercial value. Alternatively, if the concentration of inorganics is low enough or benign enough, the MSW containing the impurities can be mixed with other MSW to lower the concentration of inorganics to acceptable, safe levels. Any of these strategies is strongly dependent on exactly what the impurities are, their concentration in the MSW, and facilities available on-site.
Is the quoted 5 MW per hour, i. e., 5 MWh?
A single D4 Energy node is designed for a net output of approximately 1.25 MW of power which is based on a normal mixture of both urban and suburban households. Therefore, in order to get 5 MW, four individual energy nodes are required (4 nodes x 1.25 MW = 5 MW). In order to determine the total energy output, one must multiply the power output by the amount of time it has been producing this power. Therefore, if 5 MW output is utilized for a period of 24hours/day, then there is a total of 120 MWh of energy in a day. (24hr x 5 MW = 120 MWhr/day)
As for the unit, what is the minimum footprint requirement (12,000 sq feet) and what does the term mobile imply?
For the basic mechanical parts of the system, significantly less than 12,000 sq feet (from unloading MSW through generators, about a length of 142' and a width of 15') is needed. This is what would sit on the concrete pad. This does NOT include space for MSW storage, gas storage between the reactor portion of the system and the generators (but does include the generators and their housings), does not include the generator radiators, and does not include any miscellaneous space for plumbing, like gas manifolds. It also does not include any office space, tables, space for vehicles, etc.
Mobile means that the system can be dismantled, moved to a different location and be up and running in about 30 days. The system is skid mounted so it can be moved with a tractor/trailer.
Why is devolatization more effective?
There are several reasons as to why devolatization is more effective. Foremost, there is no combustion that releases or forms noxious compounds and it occurs in a one atmosphere system. Devolatization is also a combination of pyrolysis (devolatization in a non oxygen atmosphere) and hydropyrolysis (devolatization in a hydrogen rich atmosphere). Pyrolysis is the indirect heating of materials where no flame comes into direct contact with the material being processed. Since the reaction takes place is a non oxygen environment, the volatile part of the material is freed in the form of carbon and hydrogen molecules that reform into mostly methane gases. Moreover, this occurs in a closed-loop system; hence, there are no emissions. Devolatization also produces two valuable products, combustible gas and saleable carbon.
What is Starved Air Gasification?
Most processes that are either updraft or downdraft gasification systems are considered Starved Air Combustion. By starving or limiting the air into a thermal combustion, the material is allowed to break down into the Cs, Os and Hs to reform into Carbon Monoxide (CO) and Hydrogen (H2). If too much air is allowed the products of that combustion are pretty much CO2 and have no Btu value. In a Starved Air Combustion, CO and H2 form the syngas that can be combusted or reformed into syngas. Therefore, since Starved Air Combustion is indeed combustion, only an ash is left after the process.
What is the process for establishing or connecting to power grid?
In the United States, it is straightforward: your utility company is required to buy power from anyone who can produce it. There are typically Alternative Energy Subsidies that require the utility to pay a premium price. The generator we supply has an electrical utility interface that comes with the generator and is "out-of-the-box". The end user will need to coordinate the connection from the grid to the generator. There may be fees from the utility and an electrician may be required.
Why is the amount of Btu for the unit lower than the Btu of a standard natural gas?
The reason the gas has a 600-750 Btu value vs. the standard natural gas value of 1000 Btu is that standard natural gas is practically pure methane, and the exhaust byproducts of burning methane are exclusively water and carbon dioxide. The D4 Energy gas is between 60 and 70% methane (thus lowering its Btu value), whose products again are exclusively water and carbon dioxide. However, practically all of the remaining gas in the D4 Energy product is a combination of nitrogen and carbon dioxide, which passes through the generator unburned and unmodified. Therefore, in addition to a greater amount of carbon dioxide produced by the D4 Energy process, there will also be nitrogen. The precise quantification of this mix is (once again) highly dependent on the feedstock.