Presentation on theme: "Catalytic Conversion (via Soft Oxidation) of Methane to Ethylene Group 5."— Presentation transcript:
Catalytic Conversion (via Soft Oxidation) of Methane to Ethylene Group 5
Agenda Background Introduction Project Objectives and Production Targets Constraints and Tentative Flow Diagram Safety and Environmental Concerns Market Analysis
Introduction Why we are interested in ethylene and its derivatives? Ethylene is the world’s largest commodity chemical and the chemical industry’s fundamental building block. Ethylene and its derivatives applications
Introduction Natural gas: is abundant hydrocarbon feedstock. Methane: is the principal component of natural gas, has high hydrogen: carbon ratio.
Introduction Current approaches for the direct, large-scale chemical transformation of methane to useful chemicals: aromatization, oxyclorination, and oxidative coupling. Disadvantages: modest selectivity and yield, requirement for corrosive reagents, heat management and temperature control. New approach???
Sulfur: a soft oxidant for conversion of methane to ethylene => Using gaseous sulfur (S 2 ) as a soft oxidant can hinder the over-oxidation of methane when compared with using O 2 as oxidant.
Project Objectives With feedstock as natural gas that has the same composition in project 1, we study and maximize ethylene production from methane through oxidation conversion. CHEMCAD would be used as design simulator to assert the process and economic feasibility of the project.
Production Targets 100 molar basis of feed gas: The highest possible recovery ethylene C2H4. Minimal H 2 S release to meet environmental regulation. Minimize the formation of undesirable byproducts during the conversion of CH4 to C2H4. High ROI.
Constraints Modest selectivities and yields Heat management and temperature control Requirement for corrosive reagents Dependence on highly toxic halogenated intermediates Highly capital-intensive
GENERAL STEPS I. Reaction Site Soft oxidation of methane with sulfur II. Purification Site H 2 S absorption with DEA Regeneration of DEA III. Separation Site CS 2 removal CH 4 removal (Recycle back to feed) C 2 H 6 removal
Environmental concerns Environmental concerns Three main issues considered when dealing with the production of ethylene : Global warming Greenhouse gas effects contributed by CS 2 and CH 4 Extensive use of land Drilling pads Landscape damage Ethylene environmental hazard: C 2 H 4 can cause damage to plants and materials as a VOC
Health Concerns CS 2 Hydroca rbons H2S H2S CH 3 SH C2H4 C2H4 Potential acute health effects -Irritating to eyes, skin and respiratory system - Harmful if swallowed. -May cause burns or frostbites -Act as a simple asphyxiant Moderately irritating to eyes and skin - May cause burns or frostbites -very toxic to inhalation -Irritating to eyes -May causes severe burns or frostbites -very toxic by inhalation May causes severe burns or frostbites -acts as a simple asphyxiant. Potential chronic health effects Behavioral and neuro- physiologic al changes. -reduced nerve conduction velocity. Possible damage to heart and central nervous system Possible damage to lungs, upper respiratory tract, eyes, central nervous system Possible damage to blood, eyes, kidneys, lungs, livers, and upper respiratory tract. Possible damage to lungs,heart, Muscle tissue.
Exposure Limits Regulations OSHA: Occupational safety and Health Administration ACGIH: American Conference of Industrial Hygienists PEL: Permissible Exposure Limit ; STEL: Short-term exposure limit TWA: Time-weighted average CS 2 Hydrocarbons H 2 S CH 3 SH C 2 H 4 Permissible Exposure Limits (PEL) by OSHA STEL(1989): -12 ppm, 15 mins TWA (1989): -12 mg/m³, 8 hrs. -Not availableSTEL (1989) -21mg/m 3, 15 min - 15 ppm, 15 min TWA (2012): -1 mg/m³, 8 hrs -0.5 ppm, 8 hrs -Not available Threshold Limit values (TLV) by ACGIH TWA (2009): -1 ppm, 8 hrs TWA(2010) -1000 ppm,8hrs STEL (2010): -5ppm, 15 min TWA (2010) - 1 ppm 8hrs TWA (2012): -0.98 mg/m³, - 8 hrs. -0.5 ppm 8 hrs TWA(2010): -200 ppm 8 hrs
Safety Precautions HIGH CONTROL SYSTEMS Vibration alarms, toxic gas detectors, combustible gas or fire detectors to potential emergency situations detections Enclose operations and provide local exhaust ventilation at the site of chemical release. Provision of fire protection and emergency facilities by additional facilities for emergency shutdown and isolation. Secondary enclosures (building a vessel around the equipment) for catching leaks for storage or handling of highly toxic materials discharges, or others. Use of respiratory and protective equipment
Ethylene, Methanol and Propylene Expanding At A Rapid Pace Ethylene is the largest of the basic chemical building blocks Ethylene, propylene and methanol are expanding at a rapid pace…driven by shale in North America Benzene and chlorine showing more modest growth
Ethylene, Methanol and Propylene Expanding At A Rapid Pace 2020 Global Capacity: Ethylene:200 Million Tons Methanol:160 Million Tons Propylene:140 Million Tons
Demand for Basic Chemicals Driven By Durable/Non-durable Goods Strong economic growth supports basic chemical demand growth Modest growth in 2012/13 suggesting lower consumer spending Emerging markets are driving tomorrows demand growth China dynamics are changing, but remains critical to most markets