FERTILIZER INDUSTRY LECTURE (2) 2.5 ORGANIC FERTILIZERS:

1. Pharos University جامعه فاروس Faculty of Engineering كلية الهندسة Petrochemical Department قسم البتروكيماويات FERTILIZER INDUSTRY LECTURE (2) 2.5 ORGANIC FERTILIZERS: The title organic fertilizer refers to materials used as fertilizer that occur regularly in nature, usually as a byproduct or end product of a naturally occurring process. Organic fertilizers such as manure have been used in agriculture for thousands of years; ancient farmers did not understand the chemistry involved, but they did recognize the benefit of providing their crops with organic material.

2. Organic fertilizers typically provide the three major macronutrients required by plants: nitrogen, phosphorus, and potassium. Advantages of Organic Fertilizer: 1-limited amounts of fossil fuels are used in production, potentially lowering the amount of greenhouse gas that is released into the atmosphere. 2-The slow-release nature of most organic fertilizers may slightly decrease the runoff of nutrients into local water systems when compared to some quick-release synthetic sources

3. 3-increase the quality of the soil, including an increase in the efficiency of nutrient utilization. Disadvantages of Organic Fertilizer: 1-Generally costs significantly more than synthetic fertilizer. 2-There are not enough nutrients in organic wastes to compensate for those removed by high yielding crops and for unavoidable losses; the balance must be made up from mineral fertilizers.

4. Different Feed Stock for Fertilizers Industries • The main raw materials required for fertilizer production are natural gas, naphtha, fuel oil, and coal for the manufacture of nitrogen fertilizers; phosphate rock and sulfur for phosphate fertilizers; and potash ores for potash fertilizers. • The production of virtually all nitrogen-based fertilizers starts with the production of ammonia. There are a number of processes that produce the various fertilizers derived from ammonia, the most common of which include: urea, ammonium nitrate, urea ammonium nitrate solution, and ammoniated phosphates.

5. Ammonia is the basic building block for producing nearly all forms of nitrogen-based fertilizers. • Ammonia is produced by reacting gaseous nitrogen with hydrogen at high pressure and temperature in the presence of a catalyst. Nearly all hydrogen produced for the manufacture of nitrogen-based fertilizers is produced by reforming natural gas at a high temperature and pressure in the presence of steam and a catalyst. Hydrogen can also be produced by gasifying petroleum coke.

6. Natural Gas as a Feed Stock for Fertilizers Industries • Natural gas is a gas consisting primarily of methane (CH4). It is found as raw natural gas in underground reservoirs, as gas associated with underground reservoirs of petroleum crude oil, as undersea methane hydrates and as coal bed methane in underground coal mines. It is an important fuel source and a major feedstock for producing ammonia, hydrogen,, petrochemicals and fertilizers. Natural gas is often informally referred to as simply gas or fuel gas, especially when compared to other energy sources such as electricity.

7. Natural Gas origin 1-Million of years ago, the remains of plants and animals decayed and built up in a thick layer. This decayed matter from plants and animals is called organic material. 2- Over the time, the mud and soil changed to rock, covered the organic material and trapped it beneath the rock. 3- Pressure and heat changed some of this organic material into coal, some into oil, and some into natural gas. There are two theories that explain the formation of natural gas, biogenic and thermogenic.

8. Biogenic and thermogenic mechanisms A-Biogenic gas is formed at shallow depth and low temperatures by the anaerobic bacterial decomposition of sedimentary organic matter. B- Thermogenic gas is formed at deeper depth by: 1- Thermal cracking of sedimendary organic matter into hydrocarbon liquids and gases. (this gas is cogenetic with oil and is called primary thermogenic gas). 2- Thermal cracking of oil at higher temperatures into gas ( this gas is secondary thermogenicgas) Note: Biogenic gas consists of almost methane, but thermogenic contains methane, ethane, propane, butane and other heavier hydrocarbons.

9. Natural gas Sources • Raw natural gas is presently extracted primarily from any one of conventional underground sources, namely petroleum crude oil wells, gas wells, and condensate wells: • Raw natural gas that comes from petroleum crude oil wells is typically termed associated gas. This gas can exist separate from the crude oil in the underground formation, or dissolved in the crude oil. • Raw natural gas from gas wells and from condensate wells contains little or no crude oil and is termed non-associated gas.

10. Methane-rich gas can also come from methane deposits in the pores of some coall seams. Such gas is referred to as coalbed gas or coalbed methane (CBM) and it is also called sweet gas because it is relatively free of hydrogen sulfide. It consists mainly of methane with only trace quantities of ethane, nitrogen and carbon dioxide. It does not contain propane, butanes, pentanes or condensate. • Natural gas hydrate (also called clathrate hydrate, methane clathrate or methane hydrate) is a solid in which methane is trapped within the crystal structure of ice. Significant deposits of methane clathrate have been found under sediments on Earth’s ocean floors and in the arctic regions.

11. Composition of natural gas Raw natural gas typically consists primarily of methane (CH4), the shortest and lightest hydr0carbon molecule. It also contains varying amounts of: 1-Higher molecular weight gaseous hydrocarbons: raw natural gas may contain a total of as much as 20 volume per cent of ethane (C2H6), propane (C3H8), normal butane (n-C4H10), isobutane (i-C4H10), pentanes and even higher molecular weight hydrocarbons. When processed and purified into finished by-products, all of these are collectively referred to as NGL (Natural Gas Liquids). -

12. 2-Acid gases:carbon dioxide (CO2), hydrogen sulfide (H2S) and mercaptans such as methanethiol (CH3SH) and ethanethiol (C2H5SH). 3-Other gases:nitrogen (N2) and helium (He). 4-Water: water vapor and liquid water. 5-Liquid hydrocarbons: perhaps some natural gas condensate, a low-boiling point mixture of liquid hydrocarbons called natural gas condensate, sometimes also called natural gasoline, casinghead gasoline or simply condensate. 6-Mercury: very small amounts of mercury primarily in elemental form, but chlorides and other species are possibly present.